A solid fastening device attached to one side of a garment opening that secures the fabric by passing through a reinforced slit called a buttonhole on the overlapping side. They are manufactured from plastic, metal, wood, or shell, and attach either via pierced holes (two or four) or a concealed loop on the back (a shank). Beyond their mechanical function, they serve as prominent decorative elements on shirts, coats, and trousers.
Heard on the job
I need to replace the top button on this jacket because the original shank snapped off.